1. Field of the Invention:
This invention relates to an information transmitting device for a camera through which signals from the camera body are supplied to a photographic lens releasably attached thereto, or through which signals from the photographic lens are supplied to the camera body.
2. Description of the Prior Art:
Recently, as automation of controls of camera is advancing, particularly in the field of 35 mm lens shutter cameras, because, thanks to no need of interchanging the lens, the automatic focusing mechanism is easy to install between the lens and the camera body, auto-focus type cameras have accounted for a majority. Meanwhile, even in the field of single lens reflex cameras, a system of a camera body having an automatic focusing mechanism incorporated therein with interchangeable lenses therefor has been realized. In this case, however, it is prerequisite to provide an information transmitting device between the camera body and any one of the interchangeable lenses.
Particularly in connection with the arrangement of the ones of the parts of the aforesaid information transmitting device which take their places in the camera body, many problems have been left unsolved. For example, how to electrically connect the AF control circuit to the sequence control circuit which is arranged in the conventional manner. How to allow for checking whether or not the circuitry of the information transmitting device in isolation works normally when in the assembly line of cameras or when to remedy the malfunction of the camera. Further, how to hold a chip element in the circuit of the information transmitting device, when in isolation, on the camera body.
The AF devices for cameras may roughly be classified into active and passive types, either of which, in the present state of art, has both merits and demerits depending on photographic situations. So, in actual practice, it is difficult to say which one is superior to the other. On this account, since, in the case of single lens reflex cameras, the internal mechanism of the camera body and the mounting mechanism of the interchangeable lens both are able to accommodate respective AF detecting mechanisms, a novel camera system can be considered that the AF detecting mechanism in the camera body is, for example, of the passive type, and the one in the interchangeable lens mounting is of the active type, thus acquiring inside and outside AF functions. And, this camera system is made to operate with selection of the passive and active AF detecting modes depending on the given photographic situation, so that, as the merits of either mode are enjoyed, best AF shooting can be made. However, in such a case, how to adapt that part of the information transmitting device which is in the camera body to selective use of two different kinds of interchangeable lenses one of which is associated with the AF detecting mechanism, and the other of which lacks it, will become a large problem in future.